Infrared study of the absorption edge of {beta}-InN films grown on GaN/MgO structures

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3456171· OSTI ID:21476340

Perez-Caro, M; Rodriguez, A G; Vidal, M A; Navarro-Contreras, H ^[1]

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1. Coordinacion para la Innovacion y la Aplicacion de la Ciencia y la Tecnologia (CIACYT), Universidad Autonoma de San Luis Potosi (UASLP), Alvaro Obregon 64, San Luis Potosi, SLP 78000 (Mexico)

Infrared optical studies were carried out in a group of cubic InN samples grown by gas source molecular beam epitaxy on MgO (001) substrates. Room temperature (RT) reflectance and low-temperature (LT) transmittance measurements were performed by using fast Fourier transform infrared spectrometry. Reflectance fittings allowed to establish that {beta}-InN films have large free-carrier concentrations present (>10{sup 19} cm{sup -3}), a result that is corroborated by Hall effect measurements. Each sample explored exhibited a different optical absorption edge. The Varshni parameters that describe adequately the optical absorption edge responses with temperature are obtained for the set of samples studied. The observed temperatures changes, from LT to RT, are the lowest reported for III-V semiconductor binary compounds. The temperature coefficient of the conduction band depends on the strength of the electron-phonon interaction (e-ph-i), as well as on the thermal expansion. It has been predicted that cubic InN has one of the smallest e-ph-i of all III-V compounds, which is corroborated by these results. The variation in values of absorption edges is clearly consistent with the Burstein-Moss and band renormalization effects, produced by high free electron concentrations. It is shown that the conduction band in {beta}-InN, analogous to wurtzite InN, follows a nonparabolic behavior.

• OSTI ID: 21476340
• Journal Information: Journal of Applied Physics, Vol. 108, Issue 1; Other Information: DOI: 10.1063/1.3456171; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
ELECTRON DENSITY
ELECTRON-PHONON COUPLING
ELECTRONS
FOURIER TRANSFORMATION
GALLIUM NITRIDES
HALL EFFECT
INDIUM NITRIDES
INFRARED SPECTRA
MAGNESIUM OXIDES
MOLECULAR BEAM EPITAXY
RENORMALIZATION
SEMICONDUCTOR MATERIALS
SPECTRAL REFLECTANCE
SUBSTRATES
TEMPERATURE DEPENDENCE
THERMAL EXPANSION
THIN FILMS
VANADIUM COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
COUPLING
CRYSTAL GROWTH METHODS
ELEMENTARY PARTICLES
EPITAXY
EXPANSION
FERMIONS
FILMS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
INTEGRAL TRANSFORMATIONS
LEPTONS
MAGNESIUM COMPOUNDS
MATERIALS
NITRIDES
NITROGEN COMPOUNDS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
SPECTRA
SPECTROSCOPY
TRANSFORMATIONS
TRANSITION ELEMENT COMPOUNDS